Graphene oxide is a product of graphite powder after chemical oxidation and is a new carbon material with excellent performance. Graphene oxide is an important intermediate for chemical preparation of graphene. Additionally, graphene oxide has relatively high specific surface area and also has rich functional groups on its surface. The graphene oxide can be used to prepare composite materials with other materials.
In the preparation process of graphene oxide, a large amount of impurity ions will be inevitably introduced, such as heavy metal ions like manganese ions, iron ions, and nickel ions, etc., as well as sodium ions and potassium ions and so on. The content of impurities in graphene oxide has an important effect on its own performance and its subsequent products (such as graphene, graphene oxide-based composite materials, etc.), making it difficult to apply in fields requiring high purity graphene oxide such as the biological field, the medical field, etc.
Currently, a main purification method of graphene oxide is washing purification. However, the purification effect is not good and the impurity ion content is still high.